Diepkloof Powerline and Two Substations, Soweto, Gauteng Province
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ASSESSMENT OF VERTEBRATE SPECIES AND THEIR HABITATS FOR ESKOM'S PROPOSED NEW TAUNUS- DIEPKLOOF POWERLINE AND TWO SUBSTATIONS, SOWETO, GAUTENG PROVINCE by I.L. Rautenbach Ph.D., Pr.Nat.Sci. A.C. Kemp Ph.D., Pr.Nat.Sci. J.C.P. van Wyk M.Sc., Pr.Nat.Sci. Vertebrates and their Habitats for the Taunus-Diepkloof development Oct. 2015 Page 1 TABLE OF CONTENTS TABLE OF CONTENTS ....................................................................................... 2 List of Tables ................................................................................................................... 3 List of Figures ................................................................................................................. 4 Declaration of Independence ........................................................................................... 9 Disclaimer ..................................................................................................................... 10 EXECUTIVE SUMMARY .................................................................................... 11 1. INTRODUCTION ............................................................................................ 12 2. ASSIGNMENT – Protocol .............................................................................. 13 2.1 Initial preparations: ............................................................................................. 13 2.2 Faunal assessment .............................................................................................. 13 2.3 General ............................................................................................................... 13 3. RATIONALE ................................................................................................ 13 4. SCOPE AND OBJECTIVES OF THE STUDY ............................................. 14 5. STUDY AREA .......................................................................................... 15 5.1 Images of the proposed powerline routes and substation sites (west to east). ........ 21 6. METHODS ................................................................................................... 40 6.1 Field Survey ........................................................................................................ 40 6.2 Desktop Survey .................................................................................................. 40 6.3 Taxon-specific Requirements ............................................................................. 41 6.4 Impact Assessment Criteria ................................................................................ 41 7. RESULTS .................................................................................................... 43 7.1 MAMMALS ....................................................................................................... 43 7.1.1 Mammal Habitat Assessment .................................................................. 43 7.1.2 Observed and Expected Mammal Species Richness .............................. 44 7.1.3 Red Listed Mammal Species Identified: ................................................... 47 7.2 BIRDS ................................................................................................................ 47 7.2.1 Bird Habitat Assessment ......................................................................... 47 7.2.2 Observed and Expected Bird Species Richness ...................................... 49 7.2.3 Threatened and Red-Listed Bird Species ................................................ 59 7.3 HERPETOFAUNA ............................................................................................ 62 7.3.1 Herpetofauna Habitat Assessment .......................................................... 62 7.3.2 Observed and Expected Herpetofauna Species Richness ....................... 64 7.3.3 Red Data Listed Herpetofauna identified ................................................. 66 8. ENVIRONMENTAL IMPACT ASSESSMENT ................................................ 67 Vertebrates and their Habitats for the Taunus-Diepkloof development Oct. 2015 Page 2 8.1. The ecological importance of the study site ........................................................... 67 8.2 General impacts on vertebrates associated with transmission line construction and substation development. ................................................................................................ 68 9. IMPACT ASSESSMENT DERIVED VALUES .............................................. 71 9.1 Overall Impact Impressions ................................................................................ 72 10. LIMITATIONS, ASSUMPTIONS, GAPS IN INFORMATION AND INDEMNITY ....................................................................................................... 73 11. CONCLUSION ......................................................................................... 73 12. LITERATURE SOURCES ........................................................................ 74 13. CURRICULA VITAE ................................................................................. 79 IGNATIUS LOURENS RAUTENBACH .................................................................... 79 ALAN CHARLES KEMP ............................................................................................ 81 JACOBUS CASPARUS PETRUS (JACO) VAN WYK.............................................. 85 SACNASP Registrations: ................................................................................... 87 List of Tables Table 1: Mammal diversity. The species observed or deduced to occupy the site. (Systematics and taxonomy as proposed by Bronner et.al [2003] and Skinner and Chimimba [2005]). ................................................................................................. 46 Table 2: Mammal species positively confirmed from the study site, observed indicators and habitat............................................................................................................. 47 Table 3: Rating of recognised on-site avian habitats (site + 500 m buffer) on and around the proposed new Taunus-Diepkloof powerline and substations around Soweto, Gauteng Province (2627BB, BC, BD). ................................................................... 49 Table 4: Bird species diversity observed and expected on and around the proposed new Taunus-Diepkloof powerline and substations around Soweto, Gauteng Province (2627BB, BC, BD). Based on the national list and annotations of Birdlife South Africa (2014), sorted in the order of „Roberts VII‟ (Hockey et al. 2005), with probability of occurrence and habitat preferences assessed after a site visit on 9 June 2015 and comparison with lists from SABAP 1 & 2 (Harrison et al., 1997; www.sabap2.org). Species in bold font were detected on the site visit. ................. 50 Table 5: List of threatened species that will possibly make use of the habitats on and around the proposed new Taunus-Diepkloof powerline and substations around Soweto, Gauteng Province (2627BB, BC, BD). Note one species may have more than one habitat preference. 1+2 indicates species reported previously for site's grid cell(s) in SABAP1 up to 1992 and/or SABAP2 from 2007. ..................................... 59 Table 6: The expected frequency of occurrence of threatened bird species on and around the proposed new Taunus-Diepkloof powerline and substations around Soweto, Gauteng Province (2627BB, BC, BD), based on the quantity and quality of habitats available. 1+2 indicates species reported previously for site's grid cell(s) in SABAP1 up to 1992 and/or SABAP2 from 2007. ................................................... 60 Table 7: Estimated suitability of favoured habitats to support requirements of threatened bird species on and around the proposed new Taunus-Diepkloof powerline and substations around Soweto, Gauteng Province (2627BB, BC, BD), based on the Vertebrates and their Habitats for the Taunus-Diepkloof development Oct. 2015 Page 3 quantity and quality of habitats available and assessed as Good (G), Mediocre (M), Poor (P), Absent (A) or Not Applicable (NA). 1+2 indicates species reported previously for site's grid cell(s) in SABAP1 up to 1992 and/or SABAP2 from 2007. 60 Table 8: Reptile and Amphibian diversity. The species observed or deduced to occupy the site. Systematic arrangement and nomenclature according to Branch (1998), Minter, et.al (2004), Alexander & Marais (2007), Du Preez & Carruthers (2009) and Bates et.al (2014) .................................................................................................. 64 Table 9: Impacts expected to occur on and around the proposed and preferred new Taunus-Diepkloof powerline and substations around Soweto, Gauteng Province (2627BB, BC, BD). ................................................................................................ 70 List of Figures Figure 1: Topographical map showing the locations and routes of the proposed Taunus- Diepkloof powerline developments around Soweto, Gauteng. ............................... 12 Figure 2: Satellite image of the general area around the proposed powerline developments (red line) southwest of Johannesburg, from the Magaliesberg range in the north to the Vaal Dam in the south and across the bushveld-grassland interface (cf. Fig. 1). ............................................................................................... 15 Figure 3: Satellite image of the site (red, purple and green lines) in relation